Fiber-reinforced resin composition for parts of air intake system of internal combustion engine

ABSTRACT

Main object is to provide a composition for parts of the intake system, which is capable of enhancing the flexural elasticity modulus of the parts of the intake system and reducing the specific gravity of the parts. Disclosed is a fiber reinforced resin composition for parts of intake system on the internal combustion engine comprising a block polypropylene type resin which has a MFR in the range of 40-70 g/10 minutes (at 230° C. and under a load of 2.16 kg) and which is in the range of 60-80% by weight of the composition, and glass fibers and mica the total of which are in the range of 20-40% by weight of the composition.

TECHNICAL FIELD

The present invention relates to a fiber reinforced resin compositionfor parts of intake system on the internal combustion engine.

BACKGROUND ART

In the intake system of the internal combustion engine, provided are anair duct constituting an intake channel of the internal combustionengine, a resonater or a side branch which is provided in the intakechannel of the internal combustion engine and functions for reducingintake noise, and an air cleaner which collects dusts in the intakechannel of the internal combustion engine.

When the internal combustion engine is run and thus air is led into theinternal combustion, an intake noise may be caused by the intakesystem's parts. In order to reduce the intake noise, a technique ofenhancing the flexural elasticity modulus of the parts and thickeningthe thickness of the parts has been adapted conventionally. For example,to use a resin composition which is composed of polypropylene resin andtalc as a stiffness reinforcing material blended at about 40% by weightof the composition, and to enhance the thickness of the parts have beenadapted as the technique. However, such a technique is obliged to beaccompanied with a problem of weight increase in the parts.

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

Frequency range of the intake noise for the internal combustion engineis, for example, about 100-400 Hz and it is relatively low. We, theinventors, forcussed attention on the point that the frequency range ofintake noise for the internal combustion engine is low. Then, theinventors have been found that the resonance frequency of the intakesystem's parts can be shifted to a high frequency by enhancing theflexural elasticity modulus of the intake system's parts and reducingspecific gravity of the parts. By shifting the resonance frequency ofthe intake system's parts to a high frequency, it is possible to makethe resonance frequency of the intake system's parts far away from thefrequency range of intake noise. Thereby, the reduction of the intakenoise of the low frequency range at the intake system's parts can beattained.

Therefore, the present invention aims to provide a composition forintake system's parts, which is capable of enhancing the flexuralelasticity modulus of the intake system's parts and reducing thespecific gravity of the parts.

Means for Solving the Problems

For solving the above mentioned problems, an invention claimed in claim1 is characterized in that the composition comprises a blockpolypropylene type resin which has a MFR in the range of 40-70 g/10minutes (at 230° C. and under a load of 2.16 kg) and which is in therange of 60-80% by weight of the composition, and glass fibers and micathe total of which are in the range of 20-40% by weight of thecomposition.

Further, an invention claimed in claim 2 is characterized in that thecomposition comprises a block polypropylene type resin which has a MFRin the range of 40-70 g/10 minutes (at 230° C. and under a load of 2.16kg) and which is in the range of 58-78% by weight of the composition, anacid modified polyprene [sic] type resin which is in the range of 1-2%by weight of the composition, and glass fibers and mica the total ofwhich are in the range of 20-40% by weight of the composition.

The intake system's parts according to the present invention is any oneof an air duct constituting an intake channel of the internal combustionengine, a resonater or a side branch which is provided in the intakechannel of the internal combustion engine and functions for reducingintake noise, and an air cleaner which collects dusts in the intakechannel of internal combustion engine.

An invention claimed in claim 4 is a fiber reinforced resin compositionfor parts of intake system on the internal combustion engine which ischaracterized in that the composition comprises a block polypropylenetype resin which has a MFR in the range of 40-70 g/10 minutes (at 230°C. and under a load of 2.16 kg) and which is in the range of 60-80% byweight of the composition, and mica which is in the range of 20-40% byweight of the composition.

Effects of the Invention

According to the present invention, a fiber reinforced resin compositionfor parts of intake system on the internal combustion engine can beobtained which is able to heighten the flexural elasticity modulus ofthe intake system's parts and reduce the specific gravity of the parts.Consequently, in the intake system's parts, the intake noise can bereduced without suffering from a weight increase.

Moreover, when the composition according to this invention is used withthe aim of getting the same inertance with that of which the prior resincomposition for intake system's parts is used, the producted article canhave a lower specific gravity and a thinner thickness, and thus realizea weight loss.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an example of a pelletmanufacturing machine;

FIG. 2 are graphs showing a relation between specific gravity andinertance (FIG. 2-1), a relation between flexural elasticity modulus andinertance (FIG. 2-2) , a relation between 100 Hz elasticity modulus andinertance (FIG. 2-3), a relation between flexural elasticitymodulus/specific gravity and inertance (FIG. 2-4) , and a relationbetween 100 Hz elasticity modulus/specific gravity and inertance (FIG.2-5) respectively;

FIG. 3 are graphs showing a relation between frequency and inertance,and a relation between frequency and sound insulation level,respectively;

FIG. 4 are graphs showing relations between frequency and inertance,when the thickness of parts were varied as 2 mm, 2.5 mm, 3.0 mm, and 4.0mm; and

FIG. 5 is a graph plotted the relation between thickness and inertanceresonance frequency.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of a fiber reinforced resin composition for parts ofintake system on the internal combustion engine of the present inventionwill be described below. As the part of the intake system, any of an airduct constituting an intake channel of internal combustion engine, aresonater or a side branch which is provided in the intake channel ofinternal combustion engine and functions for reducing intake noise, andan air cleaner which collects dusts in the intake channel of theinternal combustion engine may be used.

The fiber reinforced resin composition for parts of intake system on theinternal combustion engine comprises a block polypropylene type resinwhich has a MFR in the range of 40-70 g/10 minutes (at 230° C. and undera load of 2.16 kg) and which is in the range of 60-80%by weight of thecomposition, and glass fibers and mica the total of which are in therange of 20-40% by weight of the composition.

As the type of polypropylene to be used, block polypropylene that is apolymer of propylene is used.

MFR (at 230° C. and under a load of 2.16 kg) of the polypropylene ispreferably 40-70 g/10 minutes, and more preferably 50-60 g/10 minutes.The MFR values of polypropylene used herein are determined in accordancewith JIS K-7210-1999 and under the conditions that temperature is at230° C. and a load is of 2.16 kg. If the MFR is not more than 40 g/10minutes, dispersion of glass fibers in a molded article may become wrongand the appearance of the article may fail. If the MFR is more than 60g/10 minutes, there is some possibility of being worse in impactintensity and it is not preferred.

The polymer of propylene is prepared by a slurry polymerization, a vaporphase polymerization, or a liquid phase bulk polymerization of propyleneand so on, with using a catalyst for polymerization. As the mode ofpolymerization for preparing propylene polymer, each mode of batchpolymerization and continuance polymerization can be used. The MFR ofthe polypropylene can be adjusted by multi-stage polymerization ordecomposition of the polymerizing resin.

It is preferred to blend a block polypropylene type resin having a MFRin the range of 40-70 g/10minutes and a modified polypropylene typeresin which is modified with an acid such as maleic acid, when thecomposition is prepared. The MFR of the maleic acid modifiedpolypropylene is preferably in the range of 5-800 g/10 minutes. When theMFR is too low, inferior dispersion of the resin will be occurred, andwhen the MFR is more than 800 g/10 minutes, there are some possibilitythat the impact intensity of the resin becomes low inadequately. It isdesirable that crystallization temperature (Tc) of the maleic acidmodified polypropylene is in the range of 105-125° C., and morepreferably, in the range of 110-120° C. Further, it is desirable thatadditional volume of the maleic acid is in the range of 0.1-10% byweight, and more preferably, in the range of 0.8-8% by weight.

As the glass fiber, any filament like fibers which are manufactured bymelting and spinning any glass such as E glass (Electrical glass), Cglass (Chemical glass), A glass (Alkali glass), S glass (High strengthglass), or alkali-proof glass can be used.

It is desirable that fiber diameter of the glass fiber is in the rangeof 3.-30 ,,m, and more preferably, in the range of 8-20 ,,m. When thefiber diameter is too small, the productivity of the reinforced fibersbundle would be lowered since the fibers are easy to break. Further,when pellets are manufactured continuously, such a small diameter is notpreferable because it is necessary to bundle many fibers, the work ofconnecting the fiber bundle is complicated, and the productivity isdecreased.

Fiber length of the glass fiber in the resin composition is preferablyin the range of 1.5-60 mm. For short fiber resin composition, the fiberlength is preferably in the range of 1.5-8 mm, and for long fiber resincomposition, the fiber length is preferably in the range of 12-50 mm.

As material of glass long fiber, the continuous glass fiber bundle isused, and this is commercially available as glass roving. Usually, it ispreferable that the average fiber diameter thereof is in the range of4-30 ,,m, the number of filaments to be bundled is in the range of400-10,000, Tex count is in the range of 300-20,000 g/km. Further, it isespecially preferable that the average fiber diameter is in the range of9-23 ,,m, the number of filament to be bundled is in the range of1,000-6,000.

Alternatively, as another glass fiber, a glass chopped strand can alsobe used. The glass chopped strand is usually 3-50 mm in length thereof,fiber diameter of it is about 3-25 ,,m, preferably 8-14 ,,m in fiberdiameter thereof.

It is preferable that surface treatment (for example, silane couplingagent treatment) is performed to the glass fiber in order to give orimprove an interface adhesive property of the surface of the glass fiberto the thermoplastic to be used. When the reinforced fibers treated inadvance such a treatment is used, a molded article can be expected witha good strength and appearance.

As the surface treating agent to the glass fiber, any one selectingadequately from known agents which include the so-called silane typecoupling agents and titanium type coupling agents can be used. As thesilane type compounds, amino silane and epoxy silane are used. Forexample, ,,-aminopropyl trimethoxysilane,N-,,-(aminoethyl)-,,-aminopropyl trimethoxysilane, ,,-glycidoxypropyltrimetoxysilane, ,,-(3,4-epoxycyclohexyl) ethyl trimethoxysilane vinyltriethoxysilane, vinyl-tris(beta-methoxyethoxy)silane,,,-methacryloxypropyl trimethoxysilane, ,,-(2,4-epoxycyclohexyl)ethoxymethoxysilane, ,,-(2-aminoethyl) aminopropyl trimethoxysilane,N-,,-(aminoethyl)-,,-aminopropyl trimethoxysilane, and so on areincluded. The amino type silane compounds are especially preferable.

The shape of the resin composition may be any one of powder, flake andpellet. Specific gravity of the glass fiber resin composition ispreferably 1.2 or less, and more preferably 1.15 or less. The glassfibers in the glass fiber resin composition is preferably in the rangeof 5-15% by weight, and the mica in it is preferably in the range of15-25% by weight.

Moreover, it is desirable that the resin composition comprisespolypropylene resin and the glass fibers arranged mutually in parallelsubstantially. Further, it is preferable that the resin compositioncomprises pellets the length of which is substantially equal to thelength of glass fiber included in. The pellet length of the resincomposition is preferably in the range of 2-200 mm. The pellet length ispreferably in the range of 3-100 mm, more preferably in the range of3-50 mm, and particularly preferably in the range of 6-25 mm.

Next, a preparing method of the resin composition is explained. Atfirst, resin pellets are prepared. The resin pellets can be obtainedeasily, by directing a roving which is made of thousands of the glassfibers into a impregnating die, impregnating the melting thermoplasticresin between filaments equally, and cutting to required length (2-200mm) after impregnation.

FIG. 1 shows an example of the manufacturing machine of the pellet. Forexample, a method wherein, while melted resin is supplied from anextruder 1 into the impregnating die 2 provided at the tip of anextruder 1, the continuous glass fiber bundle F is passed through theimpregnating die 2, the melting resin is impregnated into glass fiberbundle F, and then, the glass fiber bundle F is pulled out through thenozzle, and the glass fiber bundle F is pelletized in length of 2-50 mm,is used. The glass fiber bundle F is pulled out from the impregnatingdie 2 by a pulling out roll 3, and is cooled with a cooling machine 4.The glass fiber impregnating resin is pelletized by the pelletizer 5.Respective components are mixed together and dispersed in apredetermined ratio using a roll mill, a Banbury mixer, a kneader, etc.Alternatively, the components can be also dry blended using a tumblertype blender, a henschel mixer, a ribbon mixer, etc. The obtainedmixture is kneaded with a uniaxial extruder, a biaxial extruder, etc.,in order to prepare a molding material in pellet form.

To the pellet, it is possible to add various kinds of additive agents asnecessitated by use. For example, various modifiers such as dispersingagents, lubricants, plasticizers, flame retarderants, antioxidants(phenol type antioxidants, phospho-antioxidants[sic], sulfur typeantioxidants), antistatic agents, photostabilizers, ultraviolet rayabsorbents, crystallization accelerators (nucleus increasing agents),foaming agents, cross-linking agents, and antimicrobial agents, and soon; various coloring agents including pigments and dyes, such as carbonblack, titanium oxide, iron oxide red, azo pigments, anthraquinonepigments, and phthalocyanine, and so on are included as the additiveagents. These additive agents can be added into pellet at the time ofthe pellets' preparation in order to be included in the preparingpellets. Alternatively, these additive agents may be added at the timeof molded article manufacturing from the pellets.

This pellet, mica, and block polypropylene type resin having a MFR inthe range of 40-70 g/10 minutes are mixed, and then molded in order toobtain the molded article.

As the molding or forming method in order to obtain the molded article,any known molded method can be utilized unrestrictedly in anyway, suchas an injection molding method, an extrusion molding method, a blowmolding method, compression molding method, aninjection-compression-molding method, gas infusing injection molding, orfoaming injection molding, and soon. The injection molding method, thecompression molding method, and the injection-compression-molding methodare especially preferable.

EXAMPLES

The fiber reinforced resin composition was prepared using the pelletmanufacturing machine in FIG. 1.

Manufacturing Conditions

-   Die: It was attached at the tip of an extruder of diameter 50 mm,    and four rods were arranged as a straight line in the impregnating    section.-   Fiber diameter: Glass roving was used which was bundled 170 glass    fibers each having 16 ,,m in fiber diameter, the glass fibers being    surface-treated in advance with amino silane.-   Preheating temperature: 200° C.-   Thermoplastic resin: block polypropylene of MFR50+carboxylic acid    modified polypropylene.-   Melting temperature: 290° C.-   Rods: four rods, each having 6 mm(diameter)×3 mm(length).

Under the above-mentioned conditions, while amount of the fiber bundlewas regulated with tension rolls, the glass roving was provided into thedie in order to subject it to impregnation. Thereafter, it was pulledout from the die, cooled, and palletized in order to prepare a resincomposition including 50 wt. % glass fibers.

The obtained resin composition, mica M/B (mica 40%) and the abovementioned block polypropylene were dry blended with a ratio of resincomposition: mica M/B (mica 40%): block polypropylene=20:50:30. Then,the dry blended material was molded with an injection molding machine(manufactured by TOSHIBA MACHINE CO., LTD, IS80EPN) in order to obtainmolded articles. The manufacturing example was compared with comparativeexamples.

Ingredients for the individual resin compositions of the example and thecomparative examples are shown below.

Example Containing PP Used as the Base Material, Plus 10% Long FiberGlass Fiber, and 20% Mica Comparative Example 1 Containing PP Used asthe Base Material, Plus 40% Long Fiber Glass Fiber Comparative Example 2Containing PP Used as the Base Material Plus 20% Long Fiber Glass Fiber,and 30% Talc Comparative Example 3 Containing PP Used as the BaseMaterial, Plus 10% Long Fiber Glass Fiber, and 20% Talc ComparativeExample 4 Containing Nylon (PA6/PA66) Used as the Base Material, Plus10% Long Fiber Glass Fiber, and 10% Mineral Comparative Example 5Containing Nylon (PA6/PA66) Used as the Base Material, Plus 17% LongFiber Glass Fiber, and 21% Mineral Comparative Example 6 Containing PPRecycled Material Used as the Base Material, Plus 40% Talc. ComparativeExample 7 Containing PP Used as the Base Material, Plus 40% Talc

Generally, the composition of this comparative example 7 was usedconventionally.

Table 1 shows flexural elasticity modulus, weight of resin compositionwhen molded as a case and a cover for an air cleaner, and inertance withrespect to these example and comparative examples. The inertance is thetransfer function which is acquired by adding a force (F)perpendicularly to wall of the intake system, and measuring theacceleration level (a) at when the force (F) is added, and deriving fromthe level (a). Consequently, if the inertance level is low, it meansthat the face measured is hard to vibrate. TABLE 1 Typical propertyvalue Flexural Weight Contents elasticity Compare to Compare to BaseSpecific modulus comparative comparative Typical value of materialComponent gravity (Mpa) CASE example 7 COVER example 7 inartance (dB)Example PP Long fiber 1.12 6230 626.9 −11.7% 641.0 −9.6% 21.5 GF 10%/Mica 20% Comparative PP Long fiber 1.22 8750 642.6 −5.2% 682.0 −3.8%22.6 Example1 GF 40% Comparative PP Long fiber 1.36 8900 769.8 8.5%772.0 8.9% 21.1 Example2 GF 20%/ Talc 30% Comparative PP Long fiber 1.125670 630.8 −11.1% 650.5 −8.3% 23.8 Example3 GF 10%/ Talc 20% ComparativePA6/PA6 Long fiber 1.28 5380 748.3 5.4% 740.5 4.4% 36.1 Example4 (50/50)GF 10%/ Mineral 10% Comparative PA6/PA6 Long fiber 1.45 8570 844.7 19.0%838.9 18.3% 32.9 Example5 (50/50) GF 17%/ Mineral 21% Comparative PPTalc 40% 1.24 3400 706.4 −0.5% 713.9 0.7% 27.8 Example6 Recycledmaterial Comparative PP Talc 40% 1.23 4850 709.7 — 709.0 — 23.3 Example7

From Table 1, it is understood that the air cleaner of the exampleaccording to this invention can reduce the specific gravity at about 10%as compared with that of the comparative example 7used conventionally,and the inertance of the example is also low (that is, it becomes hardto vibrate). Although the lowest inertance is obtained in the case ofthe comparative example 2, the weight reduction effect is not expectedrelatively in this case because the specific gravity of this case isamply large.

FIG. 2 show a relation between specific gravity and inertance (FIG.2-1), a relation between flexural elasticity modulus and inertance (FIG.2-2), a relation between 100 Hz elasticity modulus and inertance (FIG.2-3), a relation between flexural elasticity modulus/specific gravityand inertance (FIG. 2-4), and a relation between 100 Hz elasticitymodulus/specific gravity and inertance (FIG. 2-5), respectively, withrespect to these example and comparative examples. Here, the flexuralelasticity modulus means elasticity modulus when sample is bendedslowly, and 100 Hz elasticity modulus means dynamic modulus withfrequency of 100 Hz.

There is a correlation between the flexural elasticity modulus and theinertance as-illustrated in the graphs of FIG. 2-2 and FIG. 2-3.Particularly, the 100 Hz dynamic modulus and the inertance show a moreeffective correlation.

Regarding the resin composition of the present example, since the 100 Hzdynamic modulus is high, the inertance can be reduced, and moreadvantageously, as shown in FIG. 2-1, the specific gravity is low.Conjointly these high flexural elasticity modulus and low specificgravity can reduce the noise for vibration that is the theme of thisembodiment. Contrary, in the comparative example 4 and the comparativeexample 5 in which the base material is nylon, although the flexuralelasticity modulus is high, there is a tendency that the inertance isalso high. For these results, it is hard to reduce the noise forvibration.

In FIG. 3, the present example and the comparative example 7 arecompared with respect to the relation between the frequency and theinertance, and the relation between the frequency and the soundinsulation level. The sound insulation level means the sound strengththat how much sound comes out from an air cleaner when the sound outputsfrom a speaker. The lower the sound insulation level becomes, the morethe sound insulation is performed. From these FIGS., it is found thatthe inertance and the sound insulation level in a low frequency regionare low in the example. In addition, a thickness is the same between theexample and the comparative example 7, and the weight in the example islow at about 10% as compared with that of the comparative example 7.

In FIG. 4, the present example and the comparative example 7 arecompared with respect to the relation between the frequency and theinertance when varying the thickness as 2 mm, 2.5 mm, 3.0 mm, and 4.0mm. From these FIGS., it is found that the resonance frequency can beheighten and the inertance in a low frequency region can be reduced inthe present example under the condition of the same thickness.

FIG. 5 is a graph plotted the relation between the thickness and theinertance resonance frequency with respect to the present example andthe comparative example 7. From FIG. 4, when the same resonancefrequency is obtained, nearly equal inertance levels are performed. Theexample shows an excellent level of the inertance, and when the sameinertance level as the comparative examples is intended by the presentinvention, the board thickness can be reduced from 3 mm to 2.66 mm.

In table 2, the values of the specific gravity x the thickness iscompared between the present example of which thickness is 2.66 mm andthe comparative example 7 of which thickness is 3 mm. When the sameinertance level as the comparative examples is intended by the presentinvention, it is possible to obtain the weight loss of at 19.2% in thepresent invention because of the reduced specific gravity and thinthickness which are functioned conjointly. TABLE 2 Thickness, inartanceis similar to comparative Merit for example 7 in 3 mm Specific weightMaterial Specific thickness gravity × reduction Component gravity (mm)Thickness (%) Comparative Talc 40% 1.23 3.00 3.69 — Example 7 ExampleLong fiber GF 10% + 1.12 2.66 2.98 19.2 Mica 20%

1. A fiber reinforced resin composition for parts of intake system onthe internal combustion engine comprising, a block polypropylene typeresin which has a MFR in the range of 40-70 g/10 minutes (at 230 ° C.and under a load of 2.16 kg) and which is in the range of 60-80-% byweight of the composition, and glass fibers and mica the total of whichare in the range of 20-40% by weight of the composition.
 2. A fiberreinforced resin composition for parts of intake system on the internalcombustion engine comprising, a block polypropylene type resin which hasa MFR in the range of 40-70 g/10 minutes (at 230 ° C. and under a loadof 2.16 kg) and which is in the range of 58-78% by weight of thecompositions, an acid modified polyprene [sic] type resin which is inthe range of 1-2% by weight of the composition, and glass fibers andmica the total of which are in the range of 20-40% by weight of thecomposition.
 3. The fiber reinforced resin composition for parts ofintake system on the internal combustion engine according to claim 1,the parts of the intake system is any one of an air duct constituting anintake channel of internal combustion engine, a resonater or a sidebranch which is provided in the intake channel of the internalcombustion engine and functions for reducing intake nose, and an aircleaner which collects dusts in the intake channel of the internalcombustion engine.
 4. A fiber reinforced resin composition for parts ofintake system on the internal combustion engine comprising, a blockpolypropylene type resin which has a MFR in the range of 40-70 g/10minutes (at 230° C. and under a load of 2.16 kg) and which is in therange 60-80% by weight of the composition, and mica which is in therange of 20-40% by weight of the composition.
 5. The fiber reinforcedresin composition for parts of intake system on the internal combustionengine according to claim 2, the parts of the intake system is any oneof an air duct constituting an intake channel of internal combustionengine, a resonater or a side branch which is provided in the intakechannel of the internal combustion engine and functions for reducingintake nose, and an air cleaner which collects dusts in the intakechannel of the internal combustion engine.